Tanning composition



FFEQEEZ ROGER BUCHANAN COCK, 0F GOMSTEEALL, ENGLAND, ASSIGNOB TO HIMSELF AND WILLIAIYZ VIILLOUGHBY 'WILLEAMS, 0F IBGDELVIYDDAN, RHYD-DLAN, FLINT,

ENGLAND.

No Drawing.

' To all whom it may concern:

specification.

This invention relates to an, improved method of tanning hideswhich; is particularly applicable for the production of sole leather, dressing leather and-the like, and has for its object the efiicient production of such material in a simple'and certain manner and with a greatsaving'of time compared with known methods.

The invention consists in the process of tanning treatment of hides as hereinafter described.

According to this invention the hides are treated by any ordinary process of depila tion by the use oflime, sulfide and caustic soda. They are then'fieshed and delimed in an acid bath or in old tanning liquor suf ficiently acidified for the purpose. 7 The hides are now treated according to this invention by one or other alternative 7 methods, viz., in a tanning drum or in tanning pits prov1ded with agitating means,

such as rockers or plungers.

Dealing with the treatment of hides for sole leather in the tanning drum first, for every 100 lbs. of hide the following solution is made. In two gallons of boiling water 1% lbs. of hyposulphite of soda is dissolved to which is added 1 lb. of aluminum sulphate dissolved in as little boiling water as possible. Into this mixture is stirred lb. of Vaseline or equivalent mineral product and 2 pints of glycerine or lanoline, the agitation of the whole being carried out to insure thorough mixture, which when effected is brought up to the boiling point, prefer ably by steam heat, but when such boiling oint is reached. no further heat is applied. lalf of this mixture is placed in the tanning drum, which is then filled with a liquor of 30 Barkometer, made with a tanmng extract composed of myrobolan, gambier, quebracho, and mimosa, in practically equal proportions, and to the mixture so made, one quart of turpentine is added and thoroughly mixed therewith. The hides are now placed Specificationof Letters Patent.

TANNING CGMPOSITION.

Patented J an. 3, 1922.

Application filed' october 31, 1918. Serial No. 260,568.

in the drum and the latter is revolved at a slow rate of revolution for an hour when the other half of the first described mixture is added to the drum, which latter is run for four periods of six hours each with a rest of 2 hours every sixth hour, the strength of the tanning liquor being gradually increased to 60 Barkometer by the addition of said tanning extract, great care being taken that the strength of the solution is always slowly on the increase and that the temperature of the drum does not rise above 100 F. After the drumming operation the hides are removed from the drum and laid fiat for one night and well sheeted. They are then placed in three rocker pits for 4; hours each in succession the pits containing a mixture of tanning extract and tanning liquor of 90, 100 and 120 Barkometer at a temperature of 110 F., said tanning liquor consisting of 25% myrobolan, 25% mimosa and 50% quebracho. chestnut or the like. After such treatment the hides are removed from the pits and are rinsed through acid liquor, piled ior the night. oiled with a sulphonated oil and shedded in the ordinary way.

In dealing with the hides for sole leather by pit tannage the treatment is started with a mild liquorof 20 Barkometer, composed of 60% myrobolan, 20% gambier, and 20% quebracho, chestnut or the like, and if, for example, the pit is of 250 cubic feet capacity it is filled to about i; with the above liquor. This liquor isheated, preferably by steam, to 100 F. and to it is added the following mixture 36 lbs. or" hyposulphite of soda. 24 lbs. of aluminum sulphate. '12 lbs. of Vaseline. 6 gallons of glycerine or lanoline and 2 quarts of turpentine.

which the same chemical mixture is used, but of Barkometer density. The hides are rocked in this pit for 3 hour periods with a rest of 1 hour between each for 6 hours, at a temperature of 110 F. They are then transferred to the third pit with the same chemical mixture, but of Barkometer density and are rocked at the same time and with the liquor at the same temperature as in pit No. 2. They are then transferred to the fourth pit in which a chemical mixture of double the strength of the above is used, and of Barkometer density at a temperature of F. for a period of 12 hours. No rocking takes place in this pit but the hides are handled twice over. They are then transferred to the fifth pit which contains liquor of 100 Barkometer at a temperature of F. and are kept in the pit for 12 hours and rocked for periods of 3 hours with 1 hours rest between each rocking. The hides are then finished in a similar manner to that described in the drum tannage.

process is carried out at normal atmospheric temperatures.

I claim 1. A composition for the tanning of hides, comprising hyposulphite ofsoda, aluminum sulphate, and Vaseline in the approximate proportions by weight respectively of 1.5, 1 and .5, and a mixture of glycerine, tanning extract, and turpentine in the approximate proportions by measure respectively of 1, 2000, and 1. 0 r

2. A composition for the tanning of hides, comprising, for every 100 lbs. ofhide, 14 lbs. hyposulphite of soda, 1 lb. aluminum sulphate dissolved in 2 gallons of boiling water, lb. Vaseline, 2 pints glycerine, 500 gallons of a liquor of 3060Barkometer made with tanning extract including myrobolan, gambier, quebracho and mimosa in practically equal proportions, and 2 pints of turpentine. In testimony whereof I have signed my name to this specification in the presence of two subscribin witnesses.

ROGER BUCHANAN coon. Witnesses WALTER CARVER, DORIS Hrrorroc 

